The present invention relates to fluorescent diketopyrrolopyrroles (xe2x80x9cDPPsxe2x80x9d) of the formula I 
wherein R1 and R2, independently from each other, stand for C1-C25-alkyl, allyl which can be substituted one to three times with C1-C3alkyl or Ar3, xe2x80x94CR3R4xe2x80x94(CH2)mxe2x80x94Ar3, wherein R3 and R4 independently from each other stand for hydrogen or C1-C4alkyl, or phenyl which can be substituted on to three times with C1-C3 alkyl,
Ar3 stands for phenyl or 1- or 2-naphthyl which can be substituted one to three times with C1-C8alkyl, C1-C8alkoxy, halogen or phenyl, which can be substituted with C1-C8alkyl or C1-C8alkoxy one to three times, and m stands for 0, 1, 2, 3 or 4, and wherein C1-C25-alkyl or xe2x80x94CR3R4xe2x80x94(CH2)mxe2x80x94Ar3, preferably C1-C25-alkyl, can be substituted with a functional group capable of increasing the solubility in water such as a tertiary amino group, xe2x80x94SO3xe2x80x94, or PO42xe2x88x92,
Ar1 and Ar2, independently from each other, stand for 
xe2x80x83wherein
R5 stands for C1-C6alkyl, xe2x80x94NR8R9, xe2x80x94OR10, xe2x80x94S(O)nR8, xe2x80x94Se(O)nR8, or phenyl, which can be substituted one to three times with C1-C8alkyl or C1-C8alkoxy,
wherein R8 and R9, independently from each other, stand for hydrogen, C1-C25-alkyl, C5-C12-cycloalkyl, xe2x80x94CR3R4xe2x80x94(CH2)mxe2x80x94Ph, R10, wherein R10 stands for C6-C24-aryl, or a saturated or unsaturated heterocyclic radical comprising five to seven ring atoms, wherein the ring consists of carbon atoms and one to three hetero atoms selected from the group consisting of nitrogen, oxygen and sulfur, wherein Ph, the aryl and heterocyclic radical can be substituted one to three times with C1-C8alkyl, C1-C8alkoxy, or halogen, or R8 and R9 stand for xe2x80x94C(O)R10, wherein R11 can be C1-C25-alkyl, C5-C12-cycloalkyl, R10, xe2x80x94OR12 or xe2x80x94NR13R14, wherein R12, R13, and R14 stand for C1-C25-alkyl, C5-C12-cycloalkyl, C6-C24-aryl, or
a saturated or unsaturated heterocyclic radical comprising five to seven ring atoms, wherein the ring consists of carbon atoms and one to three hetero atoms selected from the group consisting of nitrogen, oxygen and sulfur, wherein the aryl and heterocyclic radical can be substituted one to three times with C1-C8alkyl or C1-C8alkoxy, or xe2x80x94NR8R9 stands for a five- or sixmembered heterocyclic radical in which R8 and R9 together stand for tetramethylene, pentamethylehe, xe2x80x94CH2xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94CH2xe2x80x94, or xe2x80x94CH2xe2x80x94CH2xe2x80x94NR5xe2x80x94CH2xe2x80x94CH2xe2x80x94, preferably xe2x80x94CH2xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94CH2xe2x80x94, and n stands for 0, 1, 2 or 3,
and wherein R6 and R7, independently from each other, stand for hydrogen or R5, but do not stand simultaneously for hydrogen, preferably R6 stands for R5 and R7 for hydrogen.
U.S. Pat. No. 4,579,949 describes a process for the preparation of DPPs which are unsubstituted at the nitrogen atoms of the pyrrolo-rings. Especially example 45 describes the DPP-compound of the formula II 
DPP-compound II, however, is violet, exhibits only insufficient fluorescence and solubility.
Further, EP-A 133,156 claims generically DPP-compounds, however, compounds of formula I are not mentioned explicitly and no teaching is given that DPP-compounds of formula I could exhibit a red or orange fluorescence.
EP-A 499,011 describes electroluminescent devices comprising DPP-compounds. Particularly, in example 1 the DPP-derivative of formula III 
is disclosed. However, no teaching is given with regard to the fluorescence of DPP-compounds and a way to obtain DPP-compounds exhibiting a red or orange fluorescence.
WO 98/33862 describes the use of the DPP-compound of formula IV 
as a guest molecule in electroluminescent devices. However, no teaching is given with regard to the fluorescence of DPP-compounds and a way to obtain DPP-compounds exhibiting a red or orange fluorescence.
In addition, commercially available red fluorescent dyes such as thioindigo derivatives do not show superior light stability when incorporated in plastics. In addition, commercially available red fluorescent dyes cannot be applied to colour polyamides, because they decompose during the manufacturing process.
Hence, the object of this invention was to provide red or orange fluorescent compounds with a high heat stability, a good solubility in polymers, hydrocarbon based fuels, lubricants, and water, a high light stability, and the ability to be used in plastics, especially polyamides, without decomposition and loss of lightfastness, and in paints.
Accordingly, the abovementioned DPP-compounds I were found.
In addition, a process for its preparation and its use were found, too.
Red or orange fluorescent compounds means that the inventive compounds preferably have a fluorescence emission maximum in the range of from 520 to 780, more preferably from 550 to 700, more preferred from 580 to 650 nm. Further, the inventive compounds preferably exhibit an absorption in the range of 480 to 580 nm.
The inventive compounds I usually exhibit a fluorescence quantum yield (xe2x80x9cFQYxe2x80x9d) in the range of from 1 greater than FQYxe2x89xa70.3 (measured in aerated toluene or DMF). Further, in general, the inventive compounds I exhibit a molar absorption coefficient in the range of from 5000 to 100000.
A preferred embodiment relates to DPP-compounds I, wherein R1=R2, and R5=R6, R7=hydrogen, and Ar1=Ar2, particularly preferred wherein in addition to the above R3=R4=H, m=0 and n=0, most preferred are DPP-compounds in which
(a) R1=R2=C1-C8alkyl, Ar1=Ar2=phenyl or stilbene, R5=R6=xe2x80x94NR7R8 in 4-position, R7=hydrogen, and R8=R9=C1-C8alkyl or phenyl, or
(b) R1=R2=C1-C8alkyl, xe2x80x94(CH2)mxe2x80x94Ph, Ar1=Ar2=phenyl or stilbene, R5=R6=xe2x80x94SR7 or unsubstituted or substituted phenyl in para-position, and R8=C1-C8alkyl, phenyl or a heterocyclic radical, both unsubstituted or substituted, or C5-C12-cycloalkyl, or
(c) R1=R2=xe2x80x94CH2xe2x80x94Ph, wherein phenyl can be substituted with phenyl, naphthyl or C1-C4alkyl up to two times, Ar1=Ar2=phenyl or 1- or 2-naphthyl, R5=R6=R7=hydrogen, in case where Ar1=Ar2=1- or 2-naphthyl, or, in all other cases, C1-C8alkyl or phenyl.
Particularly preferred DPP-compounds I are the following compounds: 
C1-C25alkyl is typically linear or branchedxe2x80x94where possiblexe2x80x94methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl, tert.-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 1,1,3,3-tetramethylbutyl and 2-ethylhexyl, n-nonyl, decyl, undecyl, dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, eicosyl, heneicosyl, docosyl, tetracosyl or pentacosyl, preferably C1-C8alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl, tert.-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethyl-propyl, n-hexyl, n-heptyl, n-octyl, 1,1,3,3-tetramethylbutyl and 2-ethylhexyl, more preferably C1-C4alkyl such as typically methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl, tert.-butyl; C1-C3alkyl stands for methyl, ethyl, n-propyl, or isopropyl; C1-C6alkyl stands for methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, isobutyl, tert.-butyl, n-pentyl, 2-pentyl, 3-pentyl, 2,2-dimethyl-propyl, or n-hexyl.
C1-C8alkoxy is typically methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec.-butoxy, isobutoxy, tert.-butoxy, n-pentoxy, 2-pentoxy, 3-pentoxy, 2,2-dimethylpropoxy, n-hexoxy, n-heptoxy, n-octoxy, 1,1,3,3-tetramethylbutoxy and 2-ethylhexoxy, preferably C1-C4alkoxy such as typically methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec.-butoxy, isobutoxy, tert.-butoxy.
C6-C24aryl is typically phenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl, phenanthryl, 2- or 9-fluorenyl or anthracenyl, preferably C6-C12aryl such as phenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl.
C7-C24aralkyl is typically benzyl, 2-benzyl-2-propyl, xcex2-phenyl-ethyl, xcex1,xcex1-dimethylbenzyl, xcfx89-phenyl-butyl, xcfx89,xcfx89-dimethyl-xcfx89-phenyl-butyl, xcfx89-phenyl-dodecyl, xcfx89-phenyl-octadecyl, xcfx89-phenyl-eicosyl or xcfx89-phenyl-docosyl, preferably C7-C18aralkyl such as benzyl, 2-benzyl-2-propyl, xcex2-phenyl-ethyl, xcex1,xcex1-dimethylbenzyl, xcfx89-phenyl-butyl, xcfx89,xcfx89-dimethyl-xcfx89-phenyl-butyl, xcfx89-phenyl-dodecyl or xcfx89-phenyl-octadecyl, and particularly preferred C7-C12aralkyl such as benzyl, 2-benzyl-2-propyl, xcex2-phenyl-ethyl, xcex1,xcex1-dimethylbenzyl, xcfx89-phenyl-butyl, or xcfx89,xcfx89-dimethyl-xcfx89-phenyl-butyl.
C5-C12cycloalkyl is typically cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl, preferably cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl.
Heteroaryl with five to seven ring atoms, wherein nitrogen, oxygen or sulfur are the possible hetero atoms, is typically an unsaturated heterocyclic radical with five to 18 atoms having at least six conjugated xcfx80-electrons such as thienyl, benzo[b]thienyl, dibenzo[b,d]thienyl, thianthrenyl, furyl, furfuryl, 2H-pyranyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, phenoxythienyl, pyrrolyl, imidazolyl, pyrazolyl, pyridyl, bipyridyl, triazinyl, pyrimidinyl, pyrazinyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, quinolizinyl, chinolyl, isochinolyl, phthalazinyl, naphthyridinyl, chinoxalinyl, chinazolinyl, cinnolinyl, pteridinyl, carbazolyl, carbolinyl, benzotriazolyl, benzoxazolyl, phenanthridinyl, acridinyl, perimidinyl, phenanthrolinyl, phenazinyl, isothiazolyl, phenothiazinyl, isoxazolyl, furazanyl or phenoxazinyl, preferably the abovementioned mono- or bicyclic heterocyclic radicals.
The inventive DPP-compounds I can be synthesized according to methods well known in the art such as described in EP-A 133,156, e.g. in analogy to example 15.
A preferred embodiment of this invention relates to a process for the preparation of the inventive compounds I by treating in a first step the DPP derivative of formula V 
with a base, then, in a second step, treating the reaction mixture obtained in the first step with a usual alkylating agent, wherein in the first step the base is a hydride, an alkali metal alkoxide or a carbonate, and the alkylating agent is a sulfonate, tosylate, mesylate, carbonate, sulfate, or halogen compound of the formula (R1)1 or 2X, wherein X stands for SO3xe2x80x94, (p-Me-phenyl)SO2xe2x80x94, (2,4,6-trimethyl-phenyl)SO2xe2x80x94, xe2x80x94CO3xe2x80x94, xe2x80x94SO4xe2x80x94, or halogen such as chlorine, bromine or iodine, preferably chlorine, bromine or iodine, particularly preferred for bromine or iodine, or a mixture of (R1)1 or 2X and (R2)1 or 2X.
As a hydride usually an alkali metal hydride such as sodium hydride, lithium hydride, or potassium hydride, as an alkali metal alkoxide in general an alkali metal C1-C4alkoxide such as sodium or potassium tert. butoxide, sodium tert.-amylate, and as a carbonate usually sodium or potassium carbonate can be used, preferably sodium hydride.
Usually, the first step of the preferred preparation of compound I starting from compound V is carried out at a temperature in the range of from xe2x88x9225 to 100, preferably from 0 to 25xc2x0 C. Preferably, the reaction is carried out in the presence of a solvent, preferably a dipolar aprotic solvent such as carboxamides, lactams, urea derivatives, sulfones and nitrobenzene such as dimethyl formamide (xe2x80x9cDMFxe2x80x9d), dimethyl acetamide (xe2x80x9cDMAxe2x80x9d), N-methylpyrrolidone (xe2x80x9cNMPxe2x80x9d), N,Nxe2x80x2-dimethylethylene urea and N,Nxe2x80x2-dimethylpropylene urea.
In case a solvent is used, a weight ratio of solvent to DPP-compound is chosen in the range of from 100:1 to 5:1, preferably from 25:1 to 10:1.
In addition, it is preferred to carry out the first step in the presence of a phase transfer catalyst such as a tetra alkyl ammonium halide such as tetraethyl ammonium bromide.
Usually, a molar ratio of base to DPP-compound V is chosen in the range of from 10:1 to 2:1, preferably from 4:1 to 2:1.
Preferably, a molar ratio of DPP-compound V to the phase transfer catalyst is chosen in the range of from 100:1 to 5:1, preferably from 25:1 to 10:1.
Generally, the reaction time depends inter alia on the reactivity of the chosen reactants and the chosen temperature. As an example, if room temperature is chosen as reaction temperature, a reaction time is as a rule in the range of from 0.5 to 24 hours.
Preferably, the halogen compound R1xe2x80x94X (or the aforementioned mixture) is added to the reaction mixture obtained in the first step in the same solvent used in the first step.
The reaction temperature in the second process step usually is chosen in the range of from 0 to 160, preferably from 25 to 110xc2x0 C., depending on inter alia the desired reaction pressure and solvent used.
The reaction time generally is chosen in the range of from 0.5 to 120, preferably from 12 to 60 hours.
As a rule the molar ratio of R1xe2x80x94X to DPP compound V is chosen in the range of from 10:1 to 2:1, preferably from 4:1 to 2:1.
In case a solvent is used, the amount of solvent usually is chosen in the range of from 100:1 to 5:1, preferably from 25:1 to 10:1, based on the amount of halogen compound R1xe2x80x94X. Further, preferably the same solvent is used as in the first step, if a solvent is used in the first step. If no solvent is used in the first step, the same solvents can be used as mentioned above.
The obtained reaction mixture can be worked up by applying methods well known in the art, e.g. by precipitating the product in the presence of an appropriate solvent such as water, and, if deemed necessary, by re-crystallization in an appropriate solvent such as ethanol.
Other methods for example are the addition of an alcohol to quench the excess base followed by filtration.
Compounds V are described e.g. in U.S. Pat. No. 4,579,949, and/or can be prepared according to the method described therein, in which an appropriate nitrile is reacted with a corresponding dialkyl or diaryl succinate, e.g. NCxe2x80x94Ar1 is reacted with sodium tert.-amyl alcohol followed by the addition of diisopropyl succinate. This method is preferred in case Ar1 and/or Ar2 stand for a biphenyl radical (i.e. R 5 and/or R6 stand for phenyl or substituted phenyl in 4-position), or for the compounds described below (DPP VI).
Compounds I are also available in analogy to the method described in EP-A 353,184, which comprises reacting a DPP-compound of formula VI 
wherein Hal stands for halogen such as fluorine, chlorine, bromine or iodine, preferably chlorine or bromine, with a nucleophilic agent such as a secondary amine, HNR8R9, a thiol, HSR8, or HS(O)nR8, an alcohol, HOR10, a diselenide, R8(O)nSexe2x80x94Se(O)nR8, preferably in a molar ratio of DPP VI:nucleophilic agent in the range of 1.2:1 to 0.8:1, or, if R2 has the same meaning as R1 in the range of from 1:2.5 to 1:1, in the presence of an anhydrous dipolar aprotic solvent, and of an anhydrous base in an amount in the range of from usually 0.1 to 15 moles per mole of the nucleophilic agent, at a temperature in the range of from usually 100 to 220xc2x0 C. and under a pressure generally in the range of from 100 to 300 kPa.
Examples of suitable anhydrous dipolar aprotic solvents are carboxamides, lactams, urea derivatives, sulfones and nitrobenzene such as DMF, DMA, NMP, N,Nxe2x80x2-dimethylethylene urea and N,Nxe2x80x2-dimethylpropylene urea.
Suitable anhydrous bases are e.g. anhydrous organic bases such as quinoline, or preferably, an excess of the secondary amine used for the amination, the aforementioned carbonates such as sodium or potassium carbonate and alkali metal hydrides such as sodium hydride. In case a diselenide, R7(O)nSexe2x80x94Se(O)nR7, is used, an alkali metal hydride, preferably sodium hydride, has to be used as a base.
The corresponding 1- and 2-naphthyl-derivatives can be prepared analogously.
DPP-compounds VI are known and/or can be prepared e.g. according to the method described in U.S. Pat. No. 4,579,949, which methods comprises reacting a dialkyl or diaryl succinate with a nitrile, e.g. dimethyl succinate can be reacted with p-chloro benzonitrile according to example 6 in U.S. Pat. No. 4,579,949 to yield the corresponding DPP compound VI, in which Hal stands for chlorine.
Compounds R1xe2x80x94X are commercially available or can be prepared by methods well known in the art.
A further embodiment of the invention on hand concerns a process for the preparation of the inventive compounds I
(a) in treating in a first step the DPP derivative of formula VI with a nucleophilic agent such as a secondary amine, HNR8R9, a thiol, HSR8, or HS(O)nR8, an alcohol, HOR10, a diselenide, R8(O)nSexe2x80x94Se(O)nR8, preferably in a molar ratio of DPP VI:nucleophilic agent in the range of 1.2:1 to 0.8:1, or, if R2 has the same meaning as R1 in the range of from 1:2.5 to 1:1, in the presence of an anhydrous dipolar aprotic solvent, and of an anhydrous base in an amount in the range of from usually 0.1 to 15 moles per mole of the nucleophilic agent, at a temperature in the range of from usually 100 to 220xc2x0 C. and under a pressure generally in the range of from 100 to 300 kPa, and optionally isolating the obtained compound V,
(b) then treating the obtained compound V, with a base, thereafter in a second step, treating the reaction mixture obtained in the first step of (b) with an usual alkylating agent, wherein in the first step of (b) the base is a hydride, an alkali metal alkoxide or a carbonate, and the alkylating agent is a sulfonate, tosylate, mesylate, carbonate, sulfate, or halogen compound of the formula (R1)1 or 2X, wherein X stands for SO3xe2x80x94, (p-Me-phenyl)SO2xe2x80x94, (2,4,6-trimethyl-phenyl)SO2xe2x80x94, xe2x80x94CO3xe2x80x94, xe2x80x94SO4xe2x80x94, or halogen, or a mixture of (R1)1 or 2X and (R2)1 or 2X (it is evident, that the number of R1-units (either one or two) in (R1)1 or 2X depends on the nature of the chosen rest X, i.e. there can be only two R1-units if X stands for a divalent anion such as xe2x80x94CO3xe2x80x94, xe2x80x94SO4xe2x80x94 etc.).
Water-soluble compounds I, i.e. inventive compounds I being substituted with a functional group capable of increasing the solubility in water such as a tertiary amino group, SO3xe2x80x94, or PO42xe2x88x92, can be prepared by using well-known methods in the art. The following routes are representative examples, and, hence, do not restrict the invention just to these examples: 
wherein r stands for an integer from usually 2 to 25; instead of linear alkyl groups, one could also use branched alkyl groups or aralkyl groups such as Brxe2x80x94(CH2)r1aryl-(CH2)r2xe2x80x94Br, r1 and r2 usually being whole numbers in the range of from 0 to 10; 
wherein M stands for a metal ion such as sodium or potassium, and t is 1 or 2.
Another embodiment of the present invention is related to a method of coloring high molecular weight organic materials (having a molecular weight usually in the range of from 103 to 107g/mol) by incorporating the inventive fluorescent DPP compounds I by known methods in the art.
As high molecular weight organic materials the following can be used such as biopolymers, and plastic materials, including fibres.
The present invention relates preferably to the use of the inventive DPPs I for the preparation of
inks, for printing inks in printing processes, for flexographic printing, screen printing, packaging printing, security ink printing, intaglio printing or offset printing, for pre-press stages and for textile printing, for office, home applications or graphics applications, such as for paper goods, for example, for ballpoint pens, felt tips, fiber tips, card, wood, (wood) stains, metal, inking pads or inks for impact printing processes (with impact-pressure ink ribbons), for the preparation of
colorants, for coating materials, for industrial or commercial use, for textile decoration and industrial marking, for roller coatings or powder coatings or for automotive finishes, for high-solids (low-solvent), water-containing or metallic coating materials or for pigmented formulations for aqueous paints, for the preparation of
pigmented plastics for coatings, fibers, platters or mold carriers, for the preparation of
non-impact-printing material for digital printing, for the thermal wax transfer printing process, the ink jet printing process or for the thermal transfer printing process, and also for the preparation of
color filters, especially for visible light in the range from 400 to 700 nm, for liquid-crystal displays (LCDs) or charge combined devices (CCDs) or for the preparation of
cosmetics or for the preparation of
polymeric ink particles, toners, dye lasers, dry copy toners liquid copy toners, or electrophotographic toners, and electroluminescent devices.
Illustrative examples of suitable organic materials of high molecular weight which can be colored with the inventive fluorescent DPPs I of this invention are vinyl polymers, for example polystyrene, poly-xcex1-methylstyrene, poly-p-methylstyrene, poly-p-hydroxystyrene, poly-p-hydroxyphenylstyrene, polymethyl methacrylate and polyacrylamide as well as the corresponding methacrylic compounds, polymethylmaleate, polyacrylonitrile, polymethacrylonitrile, polyvinyl chloride, polyvinyl fluoride, polyvinylidene chloride, polyvinylidene fluoride, polyvinyl acetate, polymethyl vinyl ether and polybutyl vinyl ether; polymers which are derived from maleinimide and/or maleic anhydride, such as copolymers of maleic anhydride with styrene; polyvinyl pyrrolidone; ABS; ASA; polyamides; polyimides; polyamidimides; polysulfones; polyether sulfones; polyphenylene oxides; polyurethanes; polyureas; polycarbonates; polyarylenes; polyarylene sulfides; polyepoxides; polyolefins such as polyethylene and polypropylene; polyalkadienes; biopolymers and the derivatives thereof e.g. cellulose, cellulose ethers and esters such as ethylcellulose, nitrocellulose, cellulose acetate and cellulose butyrate, starch, chitin, chitosan, gelatin, zein; natural resins; synthetic resins such as alkyd resins, acrylic resins, phenolic resins, epoxide resins, aminoformaldehyde resins such as urea/formaldehyde resins and melamine/formaldehyde resin; vulcanized rubber; casein; silicone and silicone resins; rubber, chlorinated rubber; and also polymers which are used, for example, as binders in paint systems, such as novolaks which are derived from C1-C6-aldehydes such as formaldehyde and acetaldehyde and a binuclear or mononuclear, preferably mononuclear, phenol which, if desired, is substituted by one or two C1-C9alkyl groups, one or two halogen atoms or one phenyl ring, such as o-, m- or p-cresol, xylene, p-tert.-butylphenol, o-, m- or p-nonylphenol, p-chlorophenol or p-phenylphenol, or a compound having more than one phenolic group such as resorcinol, bis(4-hydroxyphenyl)methane or 2,2-bis(4-hydroxyphenyl)propane; as well as suitable mixtures of said materials.
Particularly preferred high molecular weight organic materials, in particular for the preparation of a paint system, a printing ink or ink, are, for example, cellulose ethers and esters, e.g. ethylcellulose, nitrocellulose, cellulose acetate and cellulose butyrate, natural resins or synthetic resins (polymerization or condensation resins) such as aminoplasts, in particular urea/formaldehyde and melamine/formaldehyde resins, alkyd resins, phenolic plastics, poly-carbonates, polyolefins, polystyrene, polyvinyl chloride, polyamides, polyurethanes, poly-ester, ABS, ASA, polyphenylene oxides, vulcanized rubber, casein, silicone and silicone resins as well as their possible mixtures with one another.
It is also possible to use high molecular weight organic materials in dissolved form as film formers, for example boiled linseed oil, nitrocellulose, alkyd resins, phenolic resins, melamine/formaldehyde and urea/formaldehyde resins as well as acrylic resins.
Said high molecular weight organic materials may be obtained singly or in admixture, for example in the form of granules, plastic materials, melts or in the form of solutions, in particular for the preparation of spinning solutions, paint systems, coating materials, inks or printing inks.
In a particularly preferred embodiment of this invention, the inventive fluorescent DPPs I are used for the mass coloration of polyvinyl chloride, polyamides and, especially, polyolefins such as polyethylene and polypropylene as well as for the preparation of paint systems, including powder coatings, inks, printing inks, color filters and coating colors. Illustrative examples of preferred binders for paint systems are alkyd/melamine resin paints, acryl/melamine resin paints, cellulose acetate/cellulose butyrate paints and two-pack system lacquers based on acrylic resins which are crosslinkable with polyisocyanate.
According to observations made to date, the inventive fluorescent DPPs I can be added in any desired amount to the material to be colored, depending on the end use requirements. In the case of high molecular weight organic materials, for example, the fluorescent DPPs I prepared according to this invention can be used in an amount in the range from 0.01 to 40, preferably from 0.01 to 5% by weight, based on the total weight of the colored high molecular weight organic material.
Hence, another embodiment of the present invention relates to a composition comprising
(a) 0.01 to 50, preferably 0.01 to 5, particularly preferred 0.01 to 2% by weight, based on the total weight of the colored high molecular organic material, of a fluorescent DPP I according to the present invention, and
(b) 99.99 to 50, preferably 99.99 to 95, particularly preferred 99.99 to 98% by weight, based on the total weight of the colored high molecular organic material, of a high molecular organic material, and
(c) if desired, customary additives such as rheology improvers, dispersants, fillers, paint auxiliaries, siccatives, plasticizers, UV-stabilizers, and/or additional pigments or corresponding precursors in effective amounts, such as e.g. from 0 to 50% by weight, based on the total weight of (a) and (b).
To produce non-brittle mouldings or to diminish their brittleness, so-called plasticizers can be added to the high molecular weight organic materials prior to moulding. Plasticizers may be, for example, esters of phosphoric acid, phthalic acid and sebacic acid. Said plasticizers may be added before, during or after pigmenting the high molecular weight organic materials with the inventive fluorescent DPPs I.
To obtain different shades, the inventive fluorescent DPPs I may advantageously be used in admixture with fillers, transparent and opaque white, colored and/or black pigments as well as customary luster pigments in the desired amount.
For the preparation of paints systems, coating materials, color filters, inks and printing inks, the corresponding high molecular weight organic materials, such as binders, synthetic resin dispersions etc. and the inventive fluorescent DPPs I are usually dispersed or dissolved together, if desired together with customary additives such as dispersants, fillers, paint auxiliaries, siccatives, plasticizers and/or additional pigments or pigment precursors, in a common solvent or mixture of solvents. This can be achieved by dispersing or dissolving the individual components by themselves, or also several components together, and only then bringing all components together, or by adding everything together at once.
Hence, a further embodiment of the present invention relates to a method of using the inventive fluorescent DPPs I for the preparation of dispersions and the corresponding dispersions, and paint systems, coating materials, color filters, inks and printing inks comprising the inventive fluorescent DPPs I.
A particularly preferred embodiment relates to the use of the inventive DPPs I for the preparation of fluorescent tracers for e.g. leak detection of fluids such as lubricants, cooling systems etc., as well as to fluorescent tracers or lubricants comprising the inventive DPPs I. Usually, such lubricant compositions, e.g. for a refrigerant, comprise an oil selected from the group consisting of naphthalenic oils, paraffinic oils, alkylated benzene oils, polyalkyl silicate oils, polyglycols, esters, polyether polyols, polyvinyl ethers, polycarbonates, fluorinated silicones, perfluoroethers, aromatic compounds with fluoroalkyloxy or fluoroalkylthio substituents. The amount of the inventive DPP I in the lubricant is chosen generally in an amount of from 100 to 1000 ppm. If the inventive compound I is water-soluble, it could be used as tracer in water as well.
A particular embodiment of this invention concerns ink jet inks comprising the inventive fluorescent compositions.
The desired ink may contain up to 30% by weight of the fluorescent composition, but will generally be in the range of 0.1 to 10, preferably from 0.1 to 8% by weight of the total ink composition for most thermal ink jet printing applications.
Further, the inks usually contain polymeric dispersants such as random, block, branched or graft polymers or copolymers. Most preferred are polymeric dispersants made by the group transfer polymerization process, because in general these are free from higher molecular weight species that tend to plug pen nozzles.
In AB or BAB block copolymers, the A segment usually is a hydrophobic homopolymer or copolymer which serves to link with the inventive fluorescent composition and the B block generally is a hydrophilic homopolymer or copolymer, or salts thereof and serves to disperse the pigment in the preferably chosen aqueous medium. Such polymeric dispersants and the synthesis thereof are known from e.g. U.S. Pat No. 5,085,698.
ABC triblocks are also useful as dispersants. In the ABC triblock, the A block usually is a polymer compatible with water, the B block is a polymer capable of binding to the fluorescent composition and the C block is compatible with the organic solvent. Preferably the A and C blocks are end blocks. ABC triblocks and their synthesis are disclosed e.g. in EP-A 556,649. Suitable graft polymers are disclosed in U.S. Pat. No. 5,231,131.
Representative compounds useful for this purpose include e.g. polymers of polyvinyl alcohol, cellulosics and ethylene oxide modified polymers, and dispersant compounds containing ionisable groups such as acrylic acid, maleic acid or sulfonic acid.
The polymeric dispersant is generally present in an amount in the range of from 0.1 to 30, preferably from 0,1 to 8% by weight of the total ink composition.
In addition to, or in place of the preferred polymeric dispersants, surfactants may be used as dispersants. These may be anionic, nonionic, or amphoteric surfactants. A detailed list of non-polymeric as well as some polymeric dispersants is disclosed in the section on dispersants of Manufacturing Confection Publishing Co., (1990) p. 110-129, McCutcheon""s Functional Materials, North America Edition.
Usually the ink contains an aqueous medium such as water or a mixture of water and at least one water-soluble organic solvent. Water-soluble organic solvents are well known, representative examples of which are disclosed in e.g. U.S. Pat. No. 5,085,698. Selection of a suitable mixture of water and water-soluble organic solvent depends on usually requirements of the specific application such as desired surface tension and viscosity, drying time of the ink, and the media substrate onto which the ink will be printed.
Particularly preferred is a mixture of a water-soluble solvent having at least two hydroxyl groups, e.g. diethylene glycol, and water, especially deionized water.
In the event that a mixture of water and a water-soluble organic solvent is used as aqueous medium, water usually would comprise from 30 to 95, preferably 60 to 95% by weight, based on the total weight of the aqueous medium.
The amount of aqueous medium generally is in the range of from 70 to 99.8, preferably from 84 to 99.8%, based on the total weight of the ink.
The ink may contain other ingredients well known to those skilled in the art such as surfactants to alter surface tension as well as to maximize penetration. However, because surfactants may destabilize dispersions, care should be taken to insure compatibility of the surfactant with the other ink components. In general, in aqueous inks, the surfactants may be present in amounts ranging from 0.01 to 5, preferably from 0.2 to 3% by weight, based on the total weight of the ink.
Biocides may be used in the ink compositions to inhibit growth of microorganisms. Sequestering agents such as EDTA may also be included to eliminate deleterious effects of heavy metal impurities. Other known additives, such as viscosity modifiers may also be added.
A further embodiment concerns the use of the inventive fluorescent compounds I in phase change ink jet inks. The preparation of such inks is well known in the art, e.g. described in detail in EP-A 816, 410.
For the pigmentation of high molecular weight organic material, the inventive DPPs I, optionally in the form of masterbatches, usually are mixed with the high molecular weight organic materials using roll mills, mixing apparatus or grinding apparatus. Generally, the pigmented material is subsequently brought into the desired final form by conventional processes, such as calandering, compression molding, extrusion, spreading, casting or injection molding. In order to prepare non-rigid moldings or to reduce their brittleness it is often desired to incorporate so-called plasticizers into the high molecular weight organic materials prior to forming. Examples of compounds which can be used as such plasticizers are esters of phosphoric acid, phthalic acid or sebacic acid. The plasticizers can be added before or after the incorporation of the inventive DPPs I into the polymers. It is also possible, in order to achieve different hues, to add fillers or other coloring constituents such as white, color or black pigments in desired amounts to the high molecular weight organic materials in addition to the inventive DPPs I.
For pigmenting lacquers, coating materials and printing inks the high molecular weight organic materials and the inventive DPPs I, alone or together with additives, such as fillers, other pigments, siccatives or plasticizers, are generally dissolved or dispersed in a common organic solvent or solvent mixture. In this case it is possible to adopt a procedure whereby the individual components are dispersed or dissolved individually or else two or more are dispersed or dissolved together and only then are all of the components combined.
The present invention additionally relates to inks comprising a coloristically effective amount of the pigment dispersion of the inventive DPPs I.
Processes for producing inks especially for ink jet printing are generally known and are described for example in U.S. Pat. No. 5,106,412.
The inks can be prepared, for example, by mixing the pigment dispersions comprising the inventive DPPs I with polymeric dispersants.
The mixing of the pigment dispersions with the polymeric dispersant takes place preferably in accordance with generally known methods of mixing, such as stirring or mechanical mixing; it is preferably advisable to use intensive mechanical mixers such as the so-called ULTRATURAX(copyright) stirrer from Kunkel and Jahn, Staufen (Germany).
When mixing a DPP I with polymeric dispersants it is preferred to use a water-dilutable organic solvent.
The weight ratio of the pigment dispersion to the ink in general is chosen in the range of from 0.001 to 75% by weight, preferably from 0.01 to 50% by weight, based on the overall weight of the ink.
Examples of suitable polymeric dispersants are carboxyl-containing polyacrylic resins such as polymeric methacrylic or crotonic acids, especially those obtained by addition polymerization of acrylic acid or acrylic acid and other acrylic monomers such as acrylates. Depending on the field of use or when using DPP I, it is also possible, if desired, to admix a small proportion of a water-miscible organic solvent in from 0.01 to 30% by weight, based on the overall weight of the ink, and/or to admix water and/or bases so as to give a pH in the range from 7 to 11. It may likewise be advantageous to add preservatives, antifoams, surfactants, light stabilizers and pH regulators, for example, to the ink of the invention, depending on the field of use.
Examples of suitable pH regulators are inorganic salts such as lithium hydroxide or lithium carbonate, quaternary ammonium hydroxide or ammonium carbonate. Examples of preservatives and antifoams are, for example, sodium dehydroacetate, 2,2-dimethyl-6-acetoxydioxane or ammonium thioglycolate. It is also possible to employ known agents which regulate the viscosity or the surface tension and are described in e.g. U.S. Pat. No. 5,085,698. Examples of water-miscible organic solvents are aliphatic C1-C4alcohols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert.-butanol. ketones such as acetone methyl ethyl ketone, methyl isobutyl ketone or diacetone alcohol, and also polyols, Cellosolves(copyright) and carbitols, such as ethylene glycol, diethylene glycol, triethylene glycol, glycerol, propylene gylcol, ethylene glycol monomethyl or monoethyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, ethylene glycol phenyl ether, propylene glycol phenyl ether, diethylene glycol monomethyl or monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl or monoethyl ether, and also N-methyl-2-pyrrolidone, 2-pyrrolidone, N,Nxe2x80x2-dimethylformamide or N,Nxe2x80x2-dimethylacetamide.
If desired, the ink prepared as described above can be worked up further. The working up of the ink can be carried out by the customary methods for working up dispersions, by separation techniques, such as sieving or centrifuging the coarse particles from the resulting dispersion. It has been found advantageous, too, to carry out centrifuging in two stages of different intensity, e.g. centrifuging in a first step for from ten minutes to one hour at from 2000 to 4000 rpm and then, in a second step, for from 10 minutes to one hour at from 6000 to 10000 rpm.
Following centrifuging or sieving, the dispersion usually can be used directly as an ink for ink jet printing, for example.
The present invention additionally relates to a process for producing color filters comprising a transparent substrate and applied thereon a red, blue and green layer in any desired sequence, by using a red compound I and known blue and green compounds. The different colored layers preferably exhibit patterns such that over at least 5% of their respective surface they do not overlap and with very particular preference do not overlap at all. The preparation and use of color filters or color-pigmented high molecular weight organic materials are well-known in the art and described e.g. in Displays 14/2, 1151 (1993), EP-A 784085, or GB-A 2,310,072.
The color filters can be coated for example using inks, especially printing inks, which can comprise pigment dispersions comprising the inventive DPPs I or can be prepared for example by mixing a pigment dispersion comprising a DPP I with chemically, thermally or photolytically structurable high molecular weight organic material (so-called resist). The subsequent preparation can be carried out, for example, in analogy to EP-A 654 711 by application to a substrate, such as a LCD, subsequent photostructuring and development.
Particular preference for the production of color filters is given to pigment dispersions comprising a DPP I which possess non-aqueous solvents or dispersion media for polymers.
The present invention relates, moreover, to toners comprising a pigment dispersion containing a DPP I or a high molecular weight organic material pigmented with a DPP I in a coloristically effective amount.
In a particular embodiment of the process of the invention, toners, coating materials, inks or colored plastics are prepared by processing masterbatches of toners, coating materials, inks or colored plastics in roll mills, mixing apparatus or grinding apparatus.
The present invention additionally relates to colorants, colored plastics, polymeric ink particles, or non-impact-printing material comprising an inventive DPP I pigment, preferably in the form of a dispersion, or a high molecular weight organic material pigmented with a DPP I in a coloristically effective amount.
A coloristically effective amount of the pigment dispersion according to this invention comprising an inventive DPP I denotes in general from 0.0001 to 99.99% by weight, preferably from 0.001 to 50% by weight and, with particular preference, from 0.01 to 50% by weight, based on the overall weight of the material pigmented therewith.
Further, the inventive compounds I can be used for textile application and for the dying of paper.
In contrast to known red fluorescent dyes (thioindigos) the inventive DPPs I can be applied to color polyamides, because they do not decompose during the incorporation into the polyamides. Further, they exhibit an exceptionally good lightfastness, a superior heat stability, especially in plastics.